| 摘要 |
<p>PURPOSE:To shorten a time required for erase verification by performing erase verification of plural memory elements at the same time, in a virtual ground type flash memory. CONSTITUTION:In a flash memory cell array MC having array constitution of a virtual ground type, at the time of verifying erase, a column line B5 of one end in the array MC is connected to a sense circuit amplifier through a N type MOSFETMV1, a column line B1 of the other end is connected to ground through a N type MOSFETMS1 and MS4, and a row line W1 is selected. Thereby, a current flowing from the column line B5 to the column line B1 through memory elements M11-M14 connected to the row line W1 is tested by the sense circuit amplifier, and erase verification for the memory elements M11-M14 is simultaneously performed.</p> |
